This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The phagocytosis-like process of engulfment is a key step in the sporulation pathway of the endospore forming bacteria, such as Bacillus subtilis and B. anthracis. During engulfment, the membrane of one bacterial cell (the mother cell) migrates around another, until the second cell is fully enclosed within the mother cell cytoplasm. We propose using the NCMIR to provide a higher resolution view of key steps in engulfment, including the steps of membrane migration, membrane fission and the assembly of protein complexes that play a synapse-like role coordinating signal transduction in the two cells.